@marcandre I tried pretty much every combination possible interestingly depending on the string /\A:space:*\z/ can be slower than the original regex, also afaik its not identical cause it misses some cases

I am noticing ruby head as a 20% or so faster regex going on that 2.0 for these tests

the include? method is only 30% or so percent slower than hand coding, though empty strings need special casing. Essentially include? should be short cutting if the string length is zero and returning false if the regex past in is a non-global setting one.

I love this improvement to include?, totally support it accepting regexes. Though I very much worry about consistency here.

I very much worry about having a mishmash in the language where some methods avoid global settings and others do not. The cleanest way of introducing this change is simply to allow for the new rege modifier and keep all places that accept regexes in MRI consistent.